Traffic-signal



0. A. ERDMANN. TRAFFIC SIGNAL.

I I APPLICATIQN FILEDOCT. 29, 1915. 1,307,544. v Patentedlune 24, 1919.

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0. A. ERDMANN.

TRAFFIC SIGNAL. APPLICATION FILED OCT. 29. r915.

Patented'lune 24, 1919. 3 sHEE s-sHEET 2.

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TRAFFIC SIGNAL.

. APPLICATION FILED OCT. 29,1915.

Patented June 24-, 1919.

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"UNITE STATES PATENT OFFICE.

OSCAR A. ERDMANN, OF DETROIT, MICHIGQN'.

TRAFFIC-SIGNAL.

To all whom it may concern:

Be it'known that I, OSCAR A. ERDMANN, a citizen" of the. United States, residing at Detroit, county'of Wayne, State of Michigan have invented a certain new and useful Improvement in Trafiic-Signals, and declare I the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to traiiic signals for use at street crossings to regulate movement of traflic and its object is a dev ce for use in the neighborhood of each of the four corners of two intersecting streets so arranged that two of the signaling devices are positioned to be observed by trafiic in one of the streets and on opposite sides thereof, and

- also on opposite sides of the cross-street.

while the other two aresimilarly arranged forthe-other street. As is hereinafter more fully described the two pairs of signals are so arranged that when the pair of slgnals is set to allow the traflic to move in one of the streets the other pair is simultaneously set at the same cates stop and vice-versa,

to stop-the traffic in the cross-street. Another object of the inventon, therefore, 1s a group of signals positioned in the general manner stated adapted to be jointly operated,'the pairs being so arranged as to give opposite-indications, that is, when one pair rection at the same time at the'several intersecting streets confusion oftentimes results. A further object of this lnvention, therefore,

is a signaling system involving a group of, signals at each street intersection, the several groups being arranged to operate at the same interval and display identical signals at each street inters cton so that traffic on the main street, for instance, may be signaled to go time throughout the entire dls- Specification of Letters Patent. Patented J 11116 1919. Application filed October 29, 1915. Serial No. 58,547.

trict covered by the signals and the crosstraffie at all cross streets stopped .at that same mterval'. A further object is an automatic system of signals for street trafiic.

These and other objects and the several novel features of the invention are hereinafter more fully described and claimed and shown in the accompanying drawings in which Figure l is a diagrammatic view of a street crossing indicating the general position of the group of signals and showing the circuits by means of which the same are controlled.

Fig. 2 is a diagrammatic view of several street intersections equipped with my improved signaling system.

Fig. 3 shows the general appearance of the signal when set on a post or the like.

Fig. 4 is a vertical section on line A .A of Fig. 5 of one of the signaling devices showing the general arrangement of the parts and electrical apparatus utilized to operate thesignal.

Fig; 5 is a cross-section of the signal case showlng a plan view of the operating parts.

Fig. 6 is a detail of part of the signaling apparatus utilized to lock the signal in either" go or .stop position.

Fig. 7 is a plan-view of the switch utilized with the system to produce periodic operations thereof.

Fig. 8 is a detail showing the means of operating the switch.

Fig. 9 is a detail showing the means utilized in breaking the circuit after each operation of the signal. I

Fig. 10 is a diagram showing a hand'operated switch instead of the automatlc switch indicated in Fig. 1.

Similar characters refer to similar parts throughoutthe drawing and specification,

Each individual signal consists essentially of the following parts-the general and preferred arrangement of which is shown in Figs. 4: and 5: The outer casing l is cylindrical in form and maybe arranged to be supportedinposition in any convenientmanner as on a post 2 to which the base member 3 is secured by the threaded flange 4 riveted to the base. The casing 1 has two oppositely positioned apertures 5 and 6 preferably provided with a glass cover 7 as shown to shield the interior of the case from'the elements.

The case may also be provided with a cap member 8 I preferably fitting; thereover;

Within the case is a cylindrical member hereinafter called the signal cylinder S preferably formed of light sheet metal and having four apertures 9, 10, 11 and 12, and secured to this .member preferably on the interior thereof is a cylindrical strip 18 of transparent material, as for instance celluloid, covering the four openings. The celluloid opposite the .openings 10 and 12 for instance should have the word ,Go thereon formed by white translucent letters while the celluloid opposite the apertures 9 andll should show the word Stop with letters formed in the same manner. As the signal cylinder is rotatably mounted in the casing, which casing has but two openings upon opposite sides through which a signal may be displayed,

it is evident that the signal may display either the two signal words Go or the two signal words Stop and as is hereinafter more fully shown, the signal is so positioned that the word displayed may be read only by those moving in a direction facing either display openingin the outer case 1 and the signal is not readily discernible by those moving in a direction at right angles thereto.

The signal cylinder S-is provided with a base 14 covering substantially half the cylinder and as may be seen in Fig. 4:, it is pivoted to the base 3 of the casing on the pin 15, the upper end of the cylinder is preferably closed by a cap member 16 pivoted in the cap 8 of the casing by means of a. stud 17 riding in a socket, in the cap 8'.

The signal cylinder S is designed to move one-fourth of a revolution to display either the signals 9 and 11 through the display openings in the case or the contrary signals carried at 10 and 12. In the position of the parts shown in Fig. 5, the signals appearing at the apertures 9 and 11 are displayed through the openings 5 and 6 in the case and I the cylinder is set at the limit of its movement in one direction, a pin 18 providing a stop against which the base member engages when in said position. A similar stop 19 is also provided on the opposite side of the base of the casing against which the other edge of the base 11 of the signal cylinder engages when the words appearing at the apertures 10 and 12 are brought to view through the openings 5 and 6 in the case.

To change the displayed signals from G07 to Stop or vice versa, a one-fourth revolution of the signal cylinder is required and to produce this movement I preferably prepared a pair of solenoids 20 and 21 22 and. 22 respectively to a pin- 23 and 23' respectively, each having a depending end riding in a slot 24 and 24 in the base 14 of the signal cylinder. The pin 23 is mounted in the bifurcated end of the lever 25 pivoted to the base 14 by the pin or screw 26. The pin 23 has an end riding in the slot 2-1 and is carried in the bifurcated end of the lever 27 also pivoted to the pin 26. The two levers are held in what may be termed retracted position, that is, with the pins at the outermiost ends of the slots 24 and 24, by means of a spring 28 attached to both levers and adapted to yieldably hold the same in retracted or open position. Both the levers 25 and 27 have notched ends 29 and 30 respectively, as is indicated in Figs. 5 and 6, each of which is adapted to engage behind a depending lug 31 or 32 respectively stationarily supported on a bridge member 33 ex- -tending over the base member, as shown in Figs. at and 5, and mounted at each end on brackets 34 and 35 secured to the base 3 of the casing. As may be understood from Fig. 5 when the core of the solenoid 20 is 28 and, as the cylinder S is moved around under impulse of the solenoid 20, the notch 30 of the lever 27 engages back of its respective lug 32 holding the cylinder in the display position and locking it from accidental return as the lug is fixed to the bridge and the lever pivotally fixed on the base 11 of the signal cylinder. Upon electric current passing through the solenoid 21 to draw the core to normal position therein to change the displayed signal the first movement of the core draws the lever 27 downward by reason of the movement allowed the lever by the pin 23 riding in the slot 249.. This first movement of the solenoid core thus withdraws the notch 30 from behind the lug 32 unlocking the signal cylinder, and upon the end of the pin engaging the bottom of the slot 241*, the solenoid pull is transferred to the base member 1 1 rotating it-on its pivot 15 and withdrawingthe core'of the solenoid 20.

Upon the core of the solenoid 21 reaching the limit of its movement or just prior thereto the notch 29 of the lever 25 engages behind the lug 31 locking the signal cylinder in the new position from which it is unlocked in the manner desired with the notch 30 and the lug 32. The stops 18 and'lf) are provided to prevent an overthrow of the signal due to' the impulse given by either solenoid to the signal cylinder., When the signal cylinder is turned, therefore, it engages one of the stops 18 or 19 preventing further movement in the direction of the impulse and at.a'bout-the same time one or the other notches 29 or 30 engages behind the respective lug preventing return movement, The signal cylinder is thus held: trom movement in either directionuntil unlocked by the energization of the proper solenoid.

From the foregoing it becomes evident that, by alternately energizing the solenoids,

the signal cylinder S may be made to oscillate in the casing to display the signals at the apertures 9 and 11 at one time and the signals at the apertures and 12 at asucceeding time through the display openings 5 and 6 on the outer casing. Furthermore by 'properly timing the energization of the solenoids-the signals may be set to be displayed throughout any desired interval, and

large as is possible in proportion to the diameter of the cylinder leaving but a small strip between the apertures to support the cap- 16.

' The solenoids are energized by means of a wire 50 for the solenoid 20 and a wire 51 for the solenoid 21, and common feed wire 52 shown clearly in Fig. 5. The solenoid 20 is connected with a'contact 53 on the bridge 33 by means of a connecting wire 54 and the trally pivoted at 58 solenoid 21 is electrically connected to the contact 55 by means of. the wire 56; The common wire 52 leads to a switch 57 cento the bridge. As shown in detail in Fig. 9 the switch has a depending and rearwardly extending portion 59 and on the base 14: of the signal cylinder S near the center are two pins 60" and 61, which, as the. signal cylinder is turned on its pivot, alternately engage against the side of this depending portion 59 of the switch which extends therebetween. The pins may be of insulating material but preferably are of metal incased in a fiber tube, as maybe understood from the drawing, in order to prevent. electrical connection between the switch and the signal cylinder. These pins and 61 are so spaced as to allow the signal cylinder to nearly complete its movement prior to the time that-the pin engages the projecting portion 59. The purpose of this switch'is to break the circuit to the energized solenoid upon completion of movement of the signal andlocking thereof as heretofore described. The operation of the switch is as follows :-Looking at Fig. 5, it is to be noted that the solenoid'20 has been energized and the signal set. In so doing thesignal has moved in the direction indicated by the arrow' at the right of Fig. 5, and at nearly the finish of the movement the pin 66 engages the projection 59 turnig the switch on its pivot and. breaking the connection be-' tween the end of the switch and the contact member 53 and thus breaking the circuit from the line 50, solenoid 20, line 54, contact 53, switch bar 57 to feed line '52. In breaking the contact with the plate 53, the switch is so turned as to make electrical contact with the plate 55 establishing the circuit from the line 51, solenoid 21, line 56, contact 55, switch 57 to the common line 52, so setting the mechanism for operation upon the next energization of the lines 51 and 52. This circuit is broken by the movement of the switch 57 near the finish of the movement of the core of the solenoid 21 and contact of the pin 61 with the depending portion 59 of the switch. This breaking of the circuit immediately upon the finish of the desired movement due to the energization of the solenoid in either case prevents waste of electrical current. 1

In order that the signal may be readily read at night the signal words are placed on transparent or'translucent material and are formed of transparent letters, with the surrounding material made semi-translucent by color if desired, the two signals bearing the .word Stop being of one, color and the two signals bearing the word Go being of another as is the common practice in signals (but not here shown). To illuminate the interior of the signal cylinder an electric light bulb 65 may be mounted in any con venient way as by a bar 66 mounted on the two brackets 34 and 35 as shown in ;ig. 4. The circuit for the bulbis formed y the wire 67 thereto and the wire 68 connected with the common wire 52 at the pivot point of the switch lever 57 with which said'common wire is connected. As the switch member 57 is movable the two wires 68 and 52 are preferably connected to the upper end of the pivot pin as shown.

The circuits are shown in' detail in Fig.

1, whileeach of the four signal members are only shown by two concentric circles,

a portion of each of which is blackened leaving portions indicative of the openings 4 and 5 in the outer basing and thus indicating the directions from which the individual signals are supposed to be read. The circuit wires are shown as extending to the diagrammatic representations of the signals with the understanding that these lines connect with the operating apparatus in the manner shown in Figs. 4 and 5. It may be seen in said Fig. l that-the lines 50 and 51 are connected with the individual signal members'A, B, C and D as is also the feed wire 52 and the electric light wire 67. A means of energizing the circuits 50 and 51 is indicated diagrammatically in Fig. 1, in, which the solenoid wire 50 is connected with the contact member 70 and the wire 51 is connected with a, similar contact plate 71 of an automatic switchand adjacent these con- I tact plates is a contactplate 72 to which euits of the. two solenoids,

the battery wire 73 is connected. The feed wire 52 being connected with the opposite side of the battery, by connecting the contact plates and 72 the wire 50, solenoid 20, and feed wire 52, are energized, the circuit being through the line 5-1 and the switch 57 to the feed Wire as heretofore mentioned. Likewise by connecting the contact plates 71 and 72 the wire 51 and solenoid 21, etc., are energized and by. closing the switch 74 the electric light circuit 67 and 52 is energized. The contact plates 70 and 71 and 7 2 may be closed in any convenient manner and it is to be understood to be within the spirit of this invention to connect the wires 50 or 51 with the battery wire 73 by means of a switch member 80 adapted to be connected with the terminal of the wires 50 or 51 respectively as, indicated in the diagram in Fig, 10. By this arrangement the solenoids may be alternately energized by use of a manually operated switch whereby the signals are under the control of an operator who may operate the signals as necessity demands. such as suggested in Fig. 10, one operator may manually control the operation of a group of signals.

The preferred method of alternately energizing the circuits 50 and 51 is by means of an automatic switch shown somewhat in detail in Figs. 7 and 8, and diagrammatically in Fig. 1, in which the contact platev 72 lies immediately below the'conta'ct plates 70 and 71. The three plates are not in electrical contact, the two plates 70 and 71 being insulated and the plate 72 being slightly spaced therefrom as may be understood from Fig. 8. Rotatably mounted relative to the base 85 is a switch 86 having two similar points or blades 87 adapted to pass between the two plates 70 and 71 and the plate 72 to electrically connect the same in succession as the switch rotates. The switch 86 is mounted on a shaft 88 to which is secured the bevel gear 89 meshing with a bevel pinion 90 on a horizontal shaft 91. On the opposite end of this shaft is a spur gear 92 of comparatively large diameter meshing with a gear 93 of small diameter on the shaft of a motor 94. Rotation of the motor through the gear-train described rotates the switch 86 at a predetermined rate of speed. The plates 87 of the switch are so spaced that both contact members 70 and 71 are not put into electrical contact with the plate 72 at the same time. It is to be considered that the switch is rotated in the direction shown by the arrow in Fig. 7, and the blades first make acontact between the plates 70 and 72 and then pass out from contact therewith and then in contact with the plates 71 and '72 thus alternately ener 'zing the ciry proper ar- With a hand operated switch rangement of gearing or by use of means of the required speed, the switch 86 may be made to revolveat the desired rate of speed which is preferably such that each signal is displayed for a period of about a minute. By this means the signal system is made entirely automatic, alternately showing the Go sign on a main street and then on a cross-street so that traffic is given the proper time interval to cross the intersecting street while the signal indicates movement in that direction. It is also to be understood that a greater or less time interval may be given for movement of traflic by simply altering the speed of the switch member 86.

By this orsimilar arrangement of the switch, an automatic signal system is provided and this automatic system may be continued indefinitely for a series of street intersections as indicated in Fig. 2, in which, at each of several cross streets, a group of signals is placed after the manner indicated in Fig. 1. In this diagram of Fig. 2, all the wires are not shown but a single cable is indicated for the line, and the wire system is essentially that shown in Fig. 1. By this arrangement andwith an automatic switch as above described similar signals may be similarly displayed at each of several crossings so that traflic in the main street, for instance, between each cross street is signaled to move forward at the same interval and is stopped for a succeeding interval 't0 allow movement of cross traffic. In a system where each crossing is independently 0perated, it may often happen that one crossing will signal the traflic to move forward on the main street while the next crossing on the main street has the traffic stopped and confusion may often result from such arrangement. By use of the automatic system suggested in Fig. 2 movement throughoutany single street is uniform for the dis tance controlled by the signals.

Having thus fully described my invention, its purpose and utility, what I claim and desire to secure by Letters Patent of the United States is- 1. A traflic signal for use at intersecting streets comprising two signal devices for each street on opposite sides of the inter secting point, each device consisting of a case apertured upon opposite sides through which an indication may be read by traflic moving in either direction in the street, a rotatable device in the case bearing two pairs of indications, one [pair indicating movement and the other indicating cessation of movement of traffic, a pair of solenoids adapted to oppositely actuate the rotatable device to display the indications, means whereby the circuit'energizing either solenoid is broken subsequent to actuation the circuit for the other solenoid, the severe signalsbeing soset that one pair of signals each signal, a, circuit wire common to the other solenoid of each signal, a common return wire therefor, and means for energizmg the circuit first for one set of solenoids and then for the other.-

2. In a signaling device, a casing apertured upon opposite sides, a rotatable element therewithin having a pair of signals indicating movement and a pair indicating cessation of movement of trafiic, a pair of solenoids for oppositely actuating the rotatable device, an energizing circuit for the said solenoids consisting of a circuit wire connected with one solenoid, a circuit wire connected to the other solenoid and a common return wire, a switch for closing the circuit first with one solenoid and then with the other, and a second switch within the case operated to break the circuit of energized solenoid subsequent to operation of the rotatable device thereby and closing the circuit to the other solenoid.

3. In a signaling device, a rotatable signal adapted to alternately indicate movement and cessation of movement of traflic, a pair of solenoids each adapted to turn the signal to give one indicationyan electrical circuit for each solenoid, means for alternately energizing the circuits, means actuated through movementof the signal adapted to break the circuit through the energized solenoid, and a locking device for retaining the signal in its set position.

4. In a signaling device, a signal rotatable to alternately indicate movement and cessation of movement of traflic, a pair of solenoids fixed in position relative to the signal and each adapted to-turn the signal to give one indication, an electrical circuit for each solenoid, automatic means for alternately energizing the said circuits, a pivoted lever actuated by movement. of the signalat about the completion of its movement in either direction adapted to complete the circuit to one of the solenoids and break the circuit to the other of said solenoids, and locking means for retaining the signal in either of its set positions,-the solenoid cores in each instance being connected with the signal in such manner that. the first movement of the core of the energized solenoid unlocks the signal and then'turns the same to the desired display position.

5. A traflic signal for intersecting streets comprising two signal devices for each street on opposite sides of the intersecting street, each device having two signals indicating movement and two signals indicating cessation of movement, each device being adapted to display two like signals simultaneously and the two devices in either/street being arranged to simultaneously display the same signal, the signals for one street being opposite to that of the other, an electrical circuit common to each, of the four signals adapted upon energization to actuate the signals to give the desired indication, a source of electrical energy, a., ci rcuit common to the four signals adapted upon energization to actuate the signals to give an opposite indication, and an automatic timing device for the said circuits adapted to first connect the source of energy with one of the said circuits and thereafter with'the other of the said circuits in succession at predetermined time intervals.

6. A traffic signal comprising a signal apparatus for each of a plurality of street crossings, each apparatus consisting of a group of four signals for each street crossing, there being two signals in each street on opposite sides of the intersecting street, each device having two si als indicating movement and two signals indicating a cessation-of movement and adapted to display two like signals simultaneously, the signals of one street giving an opposite indication to that of the other, a source of electrical energy, an electrical circuit common to the four signals of each of the several groups adapted upon energization to actuate the signals to display one indication and a circuit common to the four signals of each of the several groups adapted upon energization to actuate the signals to'display an opposite indication, and an automatic timing device for the circuits adapted to first connect the source of energy with one of said circuits and then with the other in succession at predetermined time intervals.

In testimony whereof I sign this specifica- .tion. 

